The long awaited judgement on Judicial Review in the Gaines-Cooper case was delivered on 16 February 2010. The good news is that the Court ruled that the guidance issued by HMRC was held to be binding on them. The bad news is that the taxpayers were unable to persuade the Court that if this guidance was applied they would be regarded as UK non resident.
In a number of recent cases, HMRC has argued that taxpayers who understood themselves to have broken UK residence actually did not do so, either because they had never left the UK or because their employment aboard was not full time. In particular HMRC appears to be challenging taxpayers whose families remain in the UK while they are working abroad.
A classic example would be that of a taxpayer whose spouse and children remained UK resident while he worked abroad, and maybe a few days in the UK each month to facilitate this arrangement. If you are in this position, you may be vulnerable to the challenge of having remained UK resident.